1. Field of the Invention
The present invention relates to an electrophotographic member for use in a developing member, a charging member and the like, a process cartridge and an electrophotographic apparatus.
2. Description of the Related Art
In an electrophotographic apparatus, a developing roller is generally configured to have an elastic layer so as to ensure a sufficient nip width with respect to a photosensitive drum to thereby stably rotate. The developing roller has a surface layer formed in order to make the toner conveying ability of a surface better and suppress toner fixation on the surface.
A charging roller which is placed while being in contact with the photosensitive drum and which allows the photosensitive drum to be charged at a predetermined potential is also generally configured to have an elastic layer and a surface layer as in the developing roller.
Meanwhile, as there is an increasing demand for more improvement in durability of an electrophotographic apparatus, there is also a demand for electrophotographic members such as a developing roller and a charging roller whose changes in performance after a long-term use are smaller.
In regard to such demands, in order to improve durability of a conductive roller in the vicinity of a surface, Japanese Patent Application Laid-Open No. H01-257881 has proposed a developing roller provided with a ceramics coating layer having a thickness of 5 μm or less on the surface of the roller. Japanese Patent Application Laid-Open No. H01-142749 has proposed a developing roller and a developer regulating member whose surfaces are coated with ceramics having titanium and tungsten atoms.